The present invention relates to the cutting and raising of submerged objects such as barges.
Lying at the bottom of many waterways, such as rivers, are submerged artificial structures which can obstruct marine navigation. Among those structures, for example, are barges which have been intentionally or accidentally sunk. Intentional sinkings have resulted from conventional techniques of erecting offshore well drilling platforms in which the platforms are floated on barges to an offshore site, whereupon the barges are sunk as a part of the platform-erecting process.
Raising of the submerged structures in one piece can be extremely difficult, especially if the structure is filled with mud and water, as is usually the case with submerged barges for example. Therefore, one practice involves raising the structure piecemeal by cutting the structure into smaller, lighter pieces. Attempts to accomplish this by divers equipped with welding torches has proved to be tedious and expensive.
Other attempts to break-up a submerged structure have included the practice of repeatedly dropping a heavy impact member such as an I-beam onto the submerged structure. The impact member contained a pointed bottom edge to facilitate a penetration of the submerged structure. The impact member, being unguided in its descent, struck the submerged structure at random locations, whereby considerable time and effort was required to break up the submerged structure.
Therefore, it would be desirable to provide methods and apparatus for facilitating and economizing the cutting and raising of submerged structures.